Conventional approaches to comminution may include use of jet mills. Jet mills may be used for grinding a range of materials, particularly in cases where the feed material is hard or already relatively fine and where high purity products, without contamination, are required. Pulverization may take place in a central toroidal chamber of the jet mill as the process material is driven around the perimeter of the chamber by multiple jets of air or steam. No grinding media may be involved. Size reduction via attrition may be the result of high-velocity collisions and resulting compressive forces between particles of the process material itself and/or between particles of the processes material and interior walls of the chamber.